Rare Earth recovery from NdFeB magnet scrap

The rare earth(RE) extraction conditions from Nd-Fe-B magnet scrap were studied by oxidation roasting -hydrochloric acid decomposition.The influence of calcination temperature and time on the iron oxidation rate was discussed in the roasting process. In the leaching process, the effects of hydrochloric acid concentration, reaction time, reaction temperature and liquid to solid ratio on leaching rate of rare earth were investigated too, and the influence of pH and the aging time of the impurity on the leaching liquid were analyzed. The results show that the oxidation rate of iron reaches maximum with calcining at 700 ℃ for 1.5 hours, and iron is completely oxidated to the trivalent iron. The RE leaching rate reaches 99.33% at the optimum conditions. After change the pH to 3.5 and the aging time to more than 2 hours for neutralization process, little impurities of Cu, Pb, Co and Fe are dissolved in the leaching solution. The Fe content in the leaching solution is only 0.0014 g/L, the rare earth leaching solution meets the requirements of RE extraction.